I am creating simple servlet and deploying it in tomcat server but I am getting the following error:
HTTP Status 500 — Error instantiating servlet class pkg.coreServlet
File Structure on the tomcat server:
webapps
|
- aarya
|
- WEB-INF
|
-web.xml
-src(folder)
|
-pkg
|
-coreServlet.class
web.xml:
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<servlet>
<servlet-name>aaryaservlet</servlet-name>
<servlet-class>pkg.coreServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>aaryaservlet</servlet-name>
<url-pattern>/coreServlet</url-pattern>
</servlet-mapping>
</web-app>
coreServlet.java:
package pkg;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class coreServlet extends HttpServlet
{
/**
*
*/
private static final long serialVersionUID = 1L;
public void doGet(HttpServletRequest req,HttpServletResponse res)
throws ServletException,IOException
{
PrintWriter out = res.getWriter();
res.setContentType("text/html");
out.println("this is First servlet Example ");
}
}
url I am giving is http://localhost:8080/aarya/coreServlet
I try by restarting tomcat but I am getting same error. Where I am doing wrong?
I’m using Tomcat8 server and i’m getting following error.
It’s url is http://localhost:8080/WeatherWebApp When i’m submitting the details then it’s giving this error.
Here is WeatherServlet.java class
package org.akshayrahar;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class WeatherServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
WeatherServlet(){
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("again");
response.setContentType("text/html");
PrintWriter out=response.getWriter();
out.println("akshay rahar");
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}
}
Here is web.xml file
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE xml>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee">
<display-name>WeatherWebApp</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>HelloServlet</servlet-name>
<servlet-class>WeatherServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>HelloServlet</servlet-name>
<url-pattern>/CurrentWeather</url-pattern>
</servlet-mapping>
</web-app>
Here is index.html file too:-
<!DOCTYPE html>
<html>
<head>
<title>Weather App</title>
<link rel="stylesheet" type="text/css" href="stylesheet.css">
<script >
function initMap() {
var input =document.getElementById('pac-input');
var autocomplete = new google.maps.places.Autocomplete(input);
}
</script>
<script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyACZhmkSaIz436Dt3kHt_cVEYKN-gHzfYo&libraries=places&callback=initMap"async defer></script>
</head>
<body>
<h1>Find weather of any city in the world</h1>
<h2>Enter City Name</h2>
<form id="form" action="CurrentWeather" method="GET">
<input id="pac-input" type="text" name="cityname">
</form><br>
<div class="button1">
<button type="submit" form="form" value="Submit">Submit</button>
</div>
</body>
</html>
I’ve also mentioned stylesheet.css file in comment. Please check it.
I am creating simple servlet and deploying it in tomcat server but I am getting the following error:
HTTP Status 500 — Error instantiating servlet class pkg.coreServlet
File Structure on the tomcat server:
webapps
|
- aarya
|
- WEB-INF
|
-web.xml
-src(folder)
|
-pkg
|
-coreServlet.class
web.xml:
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<servlet>
<servlet-name>aaryaservlet</servlet-name>
<servlet-class>pkg.coreServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>aaryaservlet</servlet-name>
<url-pattern>/coreServlet</url-pattern>
</servlet-mapping>
</web-app>
coreServlet.java:
package pkg;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class coreServlet extends HttpServlet
{
/**
*
*/
private static final long serialVersionUID = 1L;
public void doGet(HttpServletRequest req,HttpServletResponse res)
throws ServletException,IOException
{
PrintWriter out = res.getWriter();
res.setContentType("text/html");
out.println("this is First servlet Example ");
}
}
url I am giving is http://localhost:8080/aarya/coreServlet
I try by restarting tomcat but I am getting same error. Where I am doing wrong?
I just started learning Hibernate and Servlets.
I have a form (name, email), I fill that fields and the request goes to the server.
Then I fetch the data from server and print them.
This WORKS CORRECTLY!
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String name = request.getParameter("userName");
String email = request.getParameter("email");
String ip = request.getRemoteAddr();
response.getWriter().println("<html>");
response.getWriter().println("<head>");
response.getWriter().println("<title>This is a response</title>");
response.getWriter().println("<head>");
response.getWriter().println("<body>");
response.getWriter().println("<br>Your name is: " + name);
response.getWriter().println("<br>Your email is: " + email);
response.getWriter().println("<br>Your IP address is: " + ip);
response.getWriter().println("</body>");
response.getWriter().println("</html>");
}
Also I have a DB (db and .xml files are properly configured, ping is succesful, mapping is written) and Hibernate code:
public static void main(String[] args) {
AnnotationConfiguration config = new AnnotationConfiguration();
config.configure("hibernate.cfg.xml");
SessionFactory factory = config.buildSessionFactory();
Session session = factory.openSession();
session.beginTransaction();
Data data = new Data();
data.setUserName(name);
data.setUserEmail(email);
session.save(data);
session.getTransaction().commit();
session.close();
}
Also I have a Data class:
@Entity
public class Data {
@Id
@GeneratedValue
private int Id;
private String userName;
private String userEmail;
//getteres, setters...
}
But if I put this code into the Servlet, I get an HTTP error 500. The error message as I can determine it is this:
javax.servlet.ServletException: Error instantiating servlet class org.server.db.test.ServletExample org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293) org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859) org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602) org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) java.lang.Thread.run(Thread.java:722)
How can I put my info from the server to the database?
my web.xml file:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
<display-name>Example02</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<servlet>
<description></description>
<display-name>ServletExample</display-name>
<servlet-name>ServletExample</servlet-name>
<servlet-class>org.server.db.test.ServletExample</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ServletExample</servlet-name>
<url-pattern>/servlet1</url-pattern>
</servlet-mapping>
</web-app>
hibernate cfg file:
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<!-- Database connection settings -->
<property name="connection.driver_class">org.postgresql.Driver</property>
<property name="connection.url">jdbc:postgresql://localhost:5432/db</property>
<property name="connection.username">postgres</property>
<property name="connection.password">***</property>
<!-- JDBC connection pool (use the built-in) -->
<property name="connection.pool_size">2</property>
<!-- SQL dialect -->
<property name="dialect">org.hibernate.dialect.PostgreSQLDialect</property>
<!-- Enable Hibernate's current session context -->
<property name="current_session_context_class">thread</property>
<!-- Disable the second-level cache -->
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
<!-- Echo all executed SQL to stdout -->
<property name="show_sql">true</property>
<!-- Drop and re-create the database schema on startup -->
<property name="hbm2ddl.auto">create</property>
<mapping class="org.server.db.test.Data" />
<mapping class="org.server.db.test.ServletExample" />
</session-factory>
</hibernate-configuration>
Here’s the issue: I had a few projects with JSP servlets running with NetBeans 8.2. When I tried to run them in NetBeans 12.1 at a different computer, I have the error: javax.servlet.ServletException: Error instantiating servlet class.
I’ve tried to create a new web application from zero, but I still get the same error. I’ve also tried to downgrade from JDK 15 to JDK 1.8 (which worked well for me before), but doesn’t worked. I’ve even tried to upgrade from Tomcat 7 to Tomcat 9, and also switched to GlassFish, but I got the same problem.
I’ve been searching in Internet for hours looking for a solution, but I couldn’t find anyone. What could be the matter? I’ve also seen a few cuestions in StackOverflow with a similar issue but it didn’t help.
Вот мой код:
miServlet.java:
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package prueba;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
*
* @author 54113
*/
public class miServlet extends HttpServlet {
/**
* Processes requests for both HTTP <code>GET</code> and <code>POST</code>
* methods.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
/* TODO output your page here. You may use following sample code. */
out.println("<!DOCTYPE html>");
out.println("<html>");
out.println("<head>");
out.println("<title>Servlet miServlet</title>");
out.println("</head>");
out.println("<body>");
out.println("<h1>Servlet miServlet at " + request.getContextPath() + "</h1>");
out.println("</body>");
out.println("</html>");
} finally {
out.close();
}
}
// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
* Handles the HTTP <code>GET</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
response.setContentType("text/html;charser=UTF-8");
PrintWriter out = response.getWriter();
out.println("Hola");
}
/**
* Handles the HTTP <code>POST</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Returns a short description of the servlet.
*
* @return a String containing servlet description
*/
@Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>
}
index.jsp:
<%--
Document : index
Created on : 12 dic. 2020, 00:06:47
Author : 54113
--%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>JSP Page</title>
</head>
<body>
<h1>Hello World!</h1>
<h4>Haga click <a href="miServlet"> aqui </a> </h4>
</body>
</html>
web.xml:
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
<servlet>
<servlet-name>miServlet</servlet-name>
<servlet-class>prueba.miServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>miServlet</servlet-name>
<url-pattern>/miServlet</url-pattern>
</servlet-mapping>
<session-config>
<session-timeout>
30
</session-timeout>
</session-config>
</web-app>
context.xml:
<?xml version="1.0" encoding="UTF-8"?>
<Context antiJARLocking="true" path=""/>
Вот сообщения об ошибках:
С Tomcat 7:
(Примечание. Ошибка при создании экземпляра сервлета означает Ошибка при создании экземпляра класса сервлета, а ошибка внутреннего сервера не выполняется. сервер обнаружил внутреннюю ошибку, которая помешала ему выполнить этот запрос. Causa raíz означает «Основная причина»).
Estado HTTP 500 – Internal Server Error
Tipo Informe de Excepción
mensaje Error instanciando clase de servlet [prueba.miServlet]
Descripción El servidor encontró un error interno que hizo que no pudiera rellenar este requerimiento.
excepción
javax.servlet.ServletException: Error instanciando clase de servlet [prueba.miServlet]
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:492)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:1025)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:452)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1201)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:654)
org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2531)
org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2520)
java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.base/java.lang.Thread.run(Thread.java:832)
causa raíz
java.lang.RuntimeException:
prueba.miServlet.<init>(miServlet.java:1)
java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:64)
java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500)
java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:481)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:492)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:1025)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:452)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1201)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:654)
org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2531)
org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2520)
java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.base/java.lang.Thread.run(Thread.java:832)
nota La traza completa de la causa de este error se encuentra en los archivos de registro del servidor.
Apache Tomcat/7.0.107
С Tomcat 9:
Estado HTTP 500 – Internal Server Error
Tipo Informe de Excepción
mensaje Error instanciando clase de servlet [prueba.miServlet]
Descripción El servidor encontró un error interno que hizo que no pudiera rellenar este requerimiento.
excepción
javax.servlet.ServletException: Error instanciando clase de servlet [prueba.miServlet]
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:888)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1597)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.base/java.lang.Thread.run(Thread.java:832)
causa raíz
java.lang.RuntimeException:
prueba.miServlet.<init>(miServlet.java:1)
java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:64)
java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500)
java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:481)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:888)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1597)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.base/java.lang.Thread.run(Thread.java:832)
nota La traza completa de la causa de este error se encuentra en los archivos de registro del servidor.
Apache Tomcat/9.0.41
Со GlassFish:
HTTP Status 500 - Internal Server Error
type Exception report
message Internal Server Error
description The server encountered an internal error that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: Error instantiating servlet class prueba.miServlet
root cause
com.sun.enterprise.container.common.spi.util.InjectionException: Error creating managed object for class: class prueba.miServlet
root cause
java.lang.RuntimeException:
note The full stack traces of the exception and its root causes are available in the GlassFish Server Open Source Edition 5.0.1 logs.
GlassFish Server Open Source Edition 5.0.1
Finally, here’s the project’s structure:
Большое спасибо!
Лучшее
Leandro